The present invention relates to a method and a circuit arrangement for combining several digital data channels having different data rates, on a common transmission channel of a transmitter.
Transmitting data signals on a data channel with a certain frequency is known. In order to transmit a further data signal of a data channel, an additional transmission channel having a different frequency from the first transmission channel is needed. Unfortunately, if too many data signals are transmitted at the same time, there may be too few free data channels and transmission channels available to accommodate all of the data signals. Typically, in such a case, an electronic search circuit is employed to seek an available one of a plurality of transmission channels through which the desired data signal can still be transmitted. Such electronic search circuits are relatively complex. In addition, whether or not a free transmission channel can be found is a matter of chance.
Thus, there is a need for a method and device which permit a plurality of digital data channels to be transmitted over a single transmission channel, thereby eliminating the need for a search circuit.